Other issues to consider (since the discussion has gotten more broad than just the parasite concern) is providing a certain size prey for one or a few snakes would not really be possible if only feeding prekilled; the rodents grow faster than the snakes eat, and so a litter of rodents is only a suitable size for a short period of time. It would take a sizable snake collection and some really close attention to timing litters to provide prekilled prey on the regular.
Also make sure that the cost of a CO2 rig (tank and flowmeter) is budgeted in.
I raise my own mice; I need all sizes of FT, and need regular access to live and prekilled for starting hatchlings. I used to raise rats too, but at a certain point raising feeders becomes more of a chore than raising the reptiles, so I purchase frozen rats now.
There's also the psychological factor of killing rats; of all the animals I've raised (for human and animal food) and hunted, I personally find rats the most problematic to euthanize. I do really like the quality of the feeders I can produce myself, though -- I have yet to find an equivalent substitute from any supplier.